This invention relates in general to lamp assemblies and, in particular, to a lamp assembly adapted for submersion in a liquid.
More specifically, this invention relates to a submersible lamp assembly which upon submersion in liquid compresses air within the lamp housing to prevent the liquid from rising above a predetermined level into contact with an electric lamp or its electrical terminal connections positioned therein.
Lighting equipment utilized on boat trailers is continuously subjected to submersion in water when the trailer carrying the boat is manuevered into the water to allow a boat to be launched or retrieved from the water. As is well known, federal, state, and/or municipal vehicle codes require boat trailers to be equipped with signal lamps which function as tail lamps, stop lamps, turn signals, etc. These lamps are submerged in water during boat launching or loading, which is not encountered by signal lamps used on other types of vehicles.
This repetitive submersion of the signal lamp in water, especially salt water, has caused the bulb and bulb socket to corrode due to moisture which forms or becomes entrapped inside the lamp housing. The terminal connections which have heretofore been directly in contact with the water, frequently rust or corrode causing the electrical connection between the trailer electrical system and the bulb assembly to break, thereby rendering the lamp assembly inoperative.
Various attempts have been made to provide a satisfactory signal lamp assembly for use on boat trailers. Lamps such as disclosed in U.S. Pat. No. 3,106,349 and U.S. Pat. No. 3,858,039, have solved the problem of bulb and bulb socket corrosion, and bulb breakage caused by submersion of the lamp in water. However, the terminal connections in these as well as previous lamp assemblies, were located such that the terminal connections were submerged when the trailer was submerged in water. After repeated submersions of the terminal connections, the terminal connections become corroded and eventually deteriorate causing the lamp to lose its source of illuminating power.
The present invention prevents corrosion of the terminal connections, by positioning the terminal connection above the level to which water rises in the lamp housing. Thus, the terminal connections remain dry and do not come into contact with the water, which prevents corrosion of the wire connections, and provides a single location to trouble-shoot all connections.